GB1567495A - Rotary mowers - Google Patents

Description

PATENT SPECIFICATION

( 11) 1 567 495 ( 21) Application No 6720/77 ( 22) Filed 17 Feb 1977 ( 31) Convention Application No 2607666 ( 32) F ( 33) Fed Rep of Germany (DE) ( 44) Complete Specification Published 14 May 1980 ( 51) INT CL 3 AO)l D 43/1 ( O ( 52) Index at Acceptance A 1 F 232 Gi B iled 25 Feb 1976 in ( 72) Inventors: L U Di Ei R HELI-KU 1 {I.

MARTIN MAIER ( 54) IMPROVEMENTS IN ROTARY MOWERS ( 71) We, MASCHINENFABRIK FAHR AKTI El NGESELLSCHAFT GOTTMADINGEN, of 7702 Gottmadingen, District of Constance, German Federal Republic, a German Company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:-

This invention relates to rotary mowers of the kind which each have at least two pairs of mower rotors arranged side by side, the mower rotors of each pair being driven in opposite directions, and oppositely-driven conditioning rolls, on horizontal axes extending transversely of the direction of travel, behind the mower rotors.

Such a combined apparatus serves for mowing and preparing grass and similar crops, for example for the production of hay or silage.

In a rotary mower of this kind, described in German Patent Application Offenlegungschrift No 2,023,274, the two conditioning rolls of a pair are chain-driven in opposite directions but such a chain drive has the disadvantage that it is subject to dirt and wear Moreover access to the chain drive is impeded by a chain case which is difficult to seal Also, a chain drive affects the pressure between the conditioning rolls, having an opening or a closing action upon the nip of the rolls, according to the way in which it is fitted.

In this known rotary mower, one conditioning roll of each pair is mounted nondisplaceably in the machine frame while the other is mounted by its ends in roll bearers which are pivotably mounted in the machine frame and spring-loaded inwardly Since the chain has a given length, the nip of the rolls can be varied only within narrow limits.

The present invention aims to improve this known kind of rotary mower, as regards the mounting and drive of the conditioning rolls.

According to the invention there is provided a rotary mower having at least two pairs of oppositely-driven mower rotors arranged side by side and oppositely-driven conditioning rolls, on horizontal axes extending transversely of the direction of travel, behind the mower rotors, in which each pair of mower rotors has its own associated pair of conditioning rolls and driving gear in common is provided to drive the conditioning rolls each through its own cardan shaft.

The advantage of this arrangement is that each conditioning roll can be mounted variable in its position independently of the others Such a change of position is necessary for example in order to adjust the nip between the two conditioning rolls.

The invention also provides for each pair of conditioning rolls to be mounted so that it can be pivoted upward on the mower chassis, to a inoperative position, and for the cardan shafts to be of variable length.

For the above purpose, each pair of conditioning rolls may be mounted in roll bearers pivoted to the mower chassis about an axis parallel with the roll axes and means may be provided for holding each roll pair in a downward working position and an upwardly pivoted inoperative position.

The holding device may comprise a bolt to engage alternatively with sockets determining respectively the working and inoperative positions.

Provision may also be made for the conditioning rolls to be relatively adjustably mounted and they may be spring-loaded.

The upper conditioning roll of each pair mav be mounted in bearings which are displaceable in slotted guides in roll bearers by spring-loaded adjusting mechanism.

According to a further feature of the invention, the central gearing has a gear box It Z\ c ( 19) 1 567 495 formed by the mower chassis In a preferred construction, the gearing comprises an input drive shaft driving a distributor shaft driving the mower rotors and coupled to a gear box driving the cardan shafts, the gearing from the input drive shaft up to, but not including, the cardan shafts being enclosed in the mower chassis which provides an oil-bath casing therefor.

The invention will now be described with reference to a preferred example shown on the accompanying drawing, in which:Figure 1 is a diagrammatic plan view of a rotary mower according to the invention, and Figure 2 is a partially sectional side elevation of the mower, showing the mounting of the conditioning rolls.

The rotary mower as shown in the drawing is designed to be drawn by a tractor (not shown), so that it can be moved, in the direction of the arrow shown in Figure 1, over a field to be cropped.

The rotary mower has a chassis 11, extending mainly transversely of the direction of travel on which two downwardlyextending pairs of mower rotors, 12 and 13, are arranged side by side and rest on the ground by skids 14 The mower rotors have cutter blades which describe cutting circles 12 a 12 b and 13 a 13 b and are oppositely driven in pairs in the directions of the arrows shown in Figure 1.

Behind each mower rotor pair 12, 13, in the direction of travel, conditioning rolls 15, 16 are arranged symmetrically in oppositelydriven pairs The conditioning rolls 15, 16 of each pair, the axes of rotation of which are arranged horizontally and transversely of the direction of travel, are journalled at their ends in two roll bearers 5 The roll bearers 5 extend obliquely upwards, in the direction of travel and are connected with the mower chassis 11 for pivoting about an axis 1 parallel with the axes of the conditioning rolls 15 16 as explained below In Figure 2 the conditioning rolls 15, 16 are shown in the working position in which they are arranged at such a level above the ground that they receive between them the crop cut off by the respective pair of mower rotors, so as to treat the crop in the required manner.

As appears from Figure 1, the mower chassis 11 serves at the same time as an oil-bath housing for transmission gearing for driving the mower rotor pairs 12 and 13 and the conditioning roll pairs 15 16 associated therewith.

In the mower chassis 11 a distributor shaft 18, arranged horizontally and transversely of the direction of travel, is rotatably mounted and carries a bevel wheel 19 at its mid-length The bevel wheel 19 meshes with a bevel wheel 20 fast on the rear end of an input drive shaft 17 which is rotatably mounted in the mower chassis 11 and protrudes forwardly in the direction of travel The drive shaft 17, which has a cardan joint 20 a, can be coupled with the power take-off shaft (not shown) of a tractor The distributor shaft 18 also carries four bevel wheels 21 which mesh with bevel wheels 22 fast on the upper ends of drive shafts (not shown) of blades, describing the circles 12 a, 12 b and 13 a, 13 b, associated with the mower rotor pairs 12 and 13 The engagements of successive bevel wheel pairs 21, 22 alternate by 180 about the respective drive axes so that the mower rotors are driven oppositely in pairs.

Behind the distributor shaft 18, in the direction of travel, a parallel transmission shaft 23 is rotatably mounted in the mower chassis 11 which here serves as a gear box.

On the transmission shaft 23 a sprocket 24 is secured and is coupled through a chain 25 with a sprocket 26 secured on the distributor shaft 18 A pinion 27 is journalled on the transmission shaft 23 and is connected for rotation therewith through a clutch 28 serving as an overload protector The pinion 27 meshes with a pinion 29 fast on a first drive-output shaft 30 which is rotatably mounted in the mower chassis 11 behind and parallel with the transmission shaft 23.

The pinion 29 in turn meshes with a pinion 31 fast on a second drive-output shaft 32 which is rotatably mounted, behind and parallel with the first drive-output shaft 30, in the mower chassis 11 This arrangement obviously has the consequence that the first and second drive-output shafts 30 and 32 are driven in opposite directions.

The first drive-output shaft 30 is connected through two cardan shafts 33 a, 33 b with the two upper rolls 16 of each conditioning roll pair, and the second driveoutput shaft 32 is connected through two cardan shafts 34 a, 34 b with the two lower rolls 15 of each conditioning roll pair The cardan shafts 33 a 33 b, 34 a and 34 b are provided with cardan joints at both ends, and they are of two-part or telescopic formation, the two parts being axially displaceable in relation to one another but in the normal operating condition connected fast for rotation with one another The cardan shafts being of variable length permits variation of position of the conditioning rolls, independently of one another, in relation to the mower chassis 11.

Figure 1 shows, in side elevation, the mower mechanism and the arrangement of the conditioning rolls 15 16 behind a mower rotor pair 12, the conditioning rolls and their roll bearers 5 being pivotable about the axis 1 upwards into an inoperative position.

For holding the conditioning rolls 15, 16 in the working position and in the inoperative 1 567 495 position respectively, each roll bearer 5 has a bolt 2 which can be brought into engagement alternatively with sockets in the mower chassis 11 respectively defining the work.

ing position and the inoperative position of the conditioning rolls.

The adjustment of the application pressure of the upper conditioning rolls 16 of each roll pair is effected at each side by l() means of a hollow spindle 3 which is rotatably mounted in a spindle nut 4 secured on the roll bearer 5 Through a compression spring 6 the hollow spindle 3 presses upon a guide rod 7 which passes freely through the hollow spindle 3 and is firmly connected with the respective side bearing block 8 of the upper conditioning roll 16 The two bearing blocks 8 of the upper conditioning roll 16 are guided displaceably in slotted guides 10 of the two roll bearers 5 The pressure of the upper conditioning roll 16 upon the lower conditioning roll 15 can be adjusted, according to the nature and quantity of the crop, by rotation of the hollow spindles 3.

Claims (12)

WHAT WE CLAIM IS:-

1 A rotary mower having at least two pairs of oppositely-driven mower rotors arranged side by side, and oppositely-driven conditioning rolls on horizontal axes extending transversely of the direction of travel, behind the mower rotors, in which each pair of mower rotors has its own associated pair of conditioning rolls and driving gear in common is provided to drive the conditioning rolls each through its own cardan shaft.

2 A rotary mower according to claim 1, in which each pair of conditioning rolls is mounted so that it can be pivoted upward on the mower chassis and the cardan shafts are of variable length.

3 A rotary mower according to claim 2, in which each pair of conditioning rolls is mounted in roll bearers pivoted to the mower chassis about an axis parallel with the roll axes.

4 A rotary mower according to claim 2 or 3, in which means are provided for holding each roll pair in a downward working position and an upwardly pivoted inoperative position.

A rotary mower according to claim 4, in which the holding device comprises a bolt to engage alternatively with sockets determining respectively the working and inoperative positions.

6 A rotary mower according to any of claims 1 to 5, in which the conditioning rolls are relatively adjustably mounted.

7 A rotary mower according to claim 6, in which the conditioning rolls are relatively spring-loaded.

8 A rotary mower according to claim 6 or 7, in which an upper conditioning roll of each pair is mounted in bearings which are displaceable in slotted guides in roll bearers.

9 A rotary mower according to claim 8, in which the bearings of the upper roll are displaceable by spring-loaded adjusting mechanism.

A rotary mower according to any foregoing claim, in which the driving gear for the conditioning rolls has a gear box formed by the mower chassis.

11 A rotary mower according to claim 10, in which there is provided driving gear comprising an input drive shaft driving a distributor shaft driving the mower rotors and coupled to a gear box driving the cardan shafts, the gearing from the input drive shaft up to, but not including, the cardan shafts being enclosed in the mower chassis which provides an oil-bath casing therefor.

12 A rotary mower substantially as described with reference to the accompanying drawing.

PHILLIPS & LEIGH, 7, Staple Inn, Holborn, London, WC 1.

Agents for the Applicants, Chartered Patent Agents.

I'rtined for Her Majicl's Stationery Office.

N C(roydoin Prining (ompanyi Limited Croydon Surrey 1980.

P'ublished b 'I he Patent Office 25 Soutihampton Buildings.

l(o don, WC 2 A l AY, from which copnn may he obtained.